Paleobotany

Fossil evidence of spruce has been the subject of many paleobotanical studies, revealing much about the history of the taxa belonging to the genus Picea. Older studies were based primarily on macroscopic remains, which were largely reproductive organs (particularly cones and seeds) as well as vegetative parts (mainly needles and wood). Less frequent analyses include bud scales (RABIEN 1953; TOMLINSON 1985) and stomata (Trautmann 1953).

Despite the considerable number of macrofossil finds, our current knowledge of the history of spruce is shaped in large part by palynological research. This research method, taking advantage of the diagnostic characteristics of pollen grains, permits an evaluation of the abundance of spruce in the vegetative cover beginning as early as the Neogene and later Pleistocene and Holo-cene forest assemblages. The characteristic pollen grains of spruce (vesiculatae, bearing two air sacs) in central Europe permit the separate identification of P. abies and P. omorica. Furthermore, as Dyakowska (1964) demonstrates, it is possible to identify variants associated with certain regions of the contemporary geographic range of Norway spruce (Lang 1994).

Traditional methods of presenting the temporal changes in geographic ranges of tree taxa by means of pollen diagrams (cyclograms) have been complemented by the use of isopole and isochrone diagrams. The isopolar method originated with SZAFER (1935) and was developed primarily based on spruce. During the 1980's, spruce isopollen maps were developed for Europe (Hunt-LEY and Birks 1983), Poland (RALSKA-JASIEWICZOWA 1983), and for the Czech Republic and Slovakia (RybniCkova and RybniCek 1988).

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